Although there are substantial experimental,
epidemiological and clinical evidences that high
doses of ionizing radiation cause cancer and other
detrimental biological effects, the health effects of
human exposure to chronic low dose radiation
exposures are still poorly known. People in some
areas around the world live in dwellings with radiation
and radon levels as much as more than 200 times
the global average. Inhabited areas with high levels of
natural radiation are found in different areas around
the world including Yangjiang, China Kerala, India
Guarapari, Brazil and Ramsar, Iran. Ramsar in
northern Iran is among the world’s well-known areas
with highest levels of natural radiation. Annual
exposure levels in areas with elevated levels of
natural radiation in Ramsar are up to 260 mGy y-1
and average exposure rates are about 10 mGy y-1 for
a population of about 2000 residents. Due to the
local geology, which includes high levels of radium in
rocks, soils, and groundwater, Ramsar residents are
also exposed to high levels of alpha activity in the
form of ingested radium and radium decay progeny
as well as very high radon levels in their dwellings.
Based on the findings obtained by studies on the
health effect of high levels of natural radiation in
Ramsar, as well as other high background radiation
areas, no consistent detrimental effect has been
detected so far. Further research is needed to clarify
if the regulatory authorities should set limiting
regulations to protect the inhabitants against such
extraordinary elevated levels of natural radiation.
Iran. J. Radiat. Res., 2012 10 (3‐4): 111‐116
Mortazavi S, Mozdarani H. Is it time to shed some light on the black box of health policies regarding the inhabitants of the high background radiation areas of Ramsar?. Int J Radiat Res 2012; 10 (3 and 4) :111-116 URL: http://ijrr.com/article-1-976-en.html